Binderies produce paper waste in two gross categories. First, there is relatively large particulate paper waste, which paper waste results from printed paper pages being trimmed preparatory to stitching. Second, and after stitching has occurred, the bound pages are uneven. Trimming of the pages--usually with a machine known as a "three knife"--produces fine paper waste. Binderies produce a surprising tonnage of such waste, with "medium" size binderies producing from 30 to 80 tons of such waste per month.
In many small to medium size binderies, both the large paper waste and the fine paper waste are transported in carts for recycling. Thereafter, removal of the waste material from the bindery in an uncompressed format occurs by van. This results in an inordinate number of van transport trips, increasing the cost of the recycling effort.
In other bindery facilities, processing of the large paper waste and the fine paper waste occurs in a compactor at the bindery. Since this disclosure relates to compactors, a review of the compactor prior art is relevant.
Compactors are well known in the paper waste collection industry. A compactor usually charges a receiver. The receiver is a large closed container in the order of 7 feet high, 7 feet wide, and 22 feet in length. The receiver has an opening at one end in the order of 42 inches high by 60 inches wide.
The compactor includes a chute of corresponding dimension to the opening. This chute leads from the opening of the receiver, a distance away from the receiver. This chute is traversed by a 42 inch high by 60 inch wide platen powered by a hydraulic ram. This hydraulic ram powers the platen through the volume defined by the chute to compact material in the chute. Material to be compacted is placed in the chute. This material is crowded or compacted into the waste receiver.
The ram and platen are normally withdrawn from the chute. This defines a waste receiving volume between the waste receiver and platen. Waste material is dumped into this volume to be compacted until the volume is fill. When the volume to be compacted is fill, compaction of the filled volume of the chute occurs into the receiver. When fully charged with paper waste materials, the receiver can hold in the order of 9,000 to 13,000 pounds of paper waste for recycling.
It is known to have the volume to be compacted in front of the compactor platen monitored by an electric eye. When the volume to be compacted is full, the compactor cycles forward to crowd waste paper material into the receiver. Upon completion of the compacting, the ram retracts the platen to define an emptied volume to be compacted ahead of the platen. During cycling forward of the compactor platen, the volume that was the volume to be compacted is sealed by a sealing plate affixed to the top of the platen and trailing the platen. This sealing plate makes the dumping of material into the compactor behind the platen not possible when the platen of the compactor is cycling to compress material into the receiver.
As binderies increase in product volume, pneumatic transporting of fine waste particles becomes economically feasible. Unfortunately, pneumatic transport and the machines necessary to recycle the pneumatically transported fine paper waste particles are expensive. Typically, the fine paper waste particles are transported in pneumatic ducts. Transporting air pressures within the ducts are in the range of 18 inches of water. Transporting speeds in the ducts as high as 50 mph occur. The pneumatically transported paper waste materials are typically discharged at their destination through a cyclone separator to a baler exterior of the bindery facility. Balers used with such pneumatic systems are expensive, specialized pieces of equipment which compress and thereafter bind the waste. Only large bindery facilities can economically justify installation of balers.
In larger binderies, even where pneumatic transport is utilized, large paper waste is conveyed by cart to a conventional compactor and not a baler. Thus, the use of a single machine for the processing of both the large particulate waste particles and the small waste particles is not known.